Το ψητό χοιρινό είναι καλό, αλλά η αδερφή μου προτιμάει ψητά μανιτάρια.

It is functioning as a noun here: χοιρινό means pork.

Historically and grammatically, χοιρινός / χοιρινή / χοιρινό is an adjective meaning porcine or made from pork / pork-related, but in everyday Greek the neuter singular form χοιρινό is very often used by itself as a noun to mean pork.

So:

• χοιρινό = pork
• ψητό χοιρινό = roast/grilled pork

This is very common in Greek: a neuter adjective can be used as a noun.

Because they all relate to the same neuter singular idea: χοιρινό.

Greek words that belong together usually agree in gender, number, and case.

In Το ψητό χοιρινό είναι καλό:

• το = neuter singular the
• ψητό = neuter singular roasted/grilled
• χοιρινό = neuter singular pork
• καλό = neuter singular good

So Greek is showing agreement all the way through:

• το ψητό χοιρινό
• είναι καλό

In English, we do not change good depending on gender, but Greek does.

Because the adjective ψητός / ψητή / ψητό has to agree with the noun it describes.

Here are the relevant forms:

• ψητό χοιρινό = neuter singular
• ψητά μανιτάρια = neuter plural

Why?

• χοιρινό is treated as neuter singular
• μανιτάρια is neuter plural

So the adjective changes:

• singular neuter: ψητό
• plural neuter: ψητά

This is a basic Greek agreement pattern.

Because Greek often leaves out the article when speaking about something in an indefinite way, especially in the plural.

So:

• ψητά μανιτάρια = grilled mushrooms / some grilled mushrooms
• τα ψητά μανιτάρια = the grilled mushrooms

In this sentence, the idea is general: she prefers grilled mushrooms, not a specific previously mentioned plate of mushrooms.

So the version without the article sounds natural.

Because Greek usually places these short possessive words, called clitic pronouns, after the noun:

• η αδερφή μου = my sister
• το σπίτι μου = my house
• οι φίλοι μου = my friends

So μου means my, but it comes after the noun in normal Greek word order.

Literally, you can think of it as something like the sister of me, although in real Greek it simply means my sister.

Both exist.

• αδερφή is very common in Modern Greek and sounds natural in everyday language.
• αδελφή is also correct, but it can sound more formal, more conservative, or closer to older/literary usage.

So in a sentence like this, η αδερφή μου is perfectly normal.

The same happens with:

• αδερφός / αδελφός = brother

Because Greek often drops subject pronouns when they are not needed.

The verb ending already tells you the person and number, and the noun phrase η αδερφή μου already states the subject clearly.

So Greek says:

• η αδερφή μου προτιμάει...

and does not need to add αυτή for she.

If you did include αυτή, it would usually add emphasis or contrast, something like:

• She prefers mushrooms.

Greek does this a lot. Subject pronouns are often omitted unless they are needed for emphasis or clarity.

Yes, προτιμάει is correct.

Both of these can be used for he/she/it prefers:

• προτιμά
• προτιμάει

The version in your sentence, προτιμάει, is very common in everyday Modern Greek.

So:

• η αδερφή μου προτιμά = my sister prefers
• η αδερφή μου προτιμάει = my sister prefers

Both are acceptable. The choice is often a matter of style, rhythm, or personal preference.

Here is the case structure:

• Το ψητό χοιρινό = nominative, because it is the subject of είναι
• η αδερφή μου = nominative, because it is the subject of προτιμάει
• ψητά μανιτάρια = accusative, because it is the direct object of προτιμάει

A useful thing to notice is that for neuter plural nouns like μανιτάρια, the nominative and accusative forms are the same. So you do not see a visible change here.

That is why ψητά μανιτάρια looks the way it does.

Yes, Greek can place adjectives before or after the noun, but the effect can be a little different.

The most neutral version here is:

• ψητά μανιτάρια

You may also hear:

• μανιτάρια ψητά

Putting the adjective after the noun can sometimes sound more descriptive, more contrastive, or more stylistically marked, depending on context.

For a learner, the safest default is:

• article + adjective + noun
  or
• adjective + noun

So ψητά μανιτάρια is the best basic pattern to remember here.

Ψητός / ψητή / ψητό comes from ψήνω, which is a cooking verb covering the general idea of cooking by dry heat.

Depending on context, ψητό can be translated as:

• roasted
• grilled
• sometimes baked

So the exact English word depends on the food and the situation.

In this sentence:

• ψητό χοιρινό could be roast pork or grilled pork
• ψητά μανιτάρια could be grilled mushrooms or roasted mushrooms

English chooses the most natural food word; Greek uses ψητό/ψητά more broadly.

Two sounds often stand out to English speakers:

• ψ in ψητό
• χ in χοιρινό

ψ is pronounced like ps together, as in the end of lapse, but at the beginning of the word:

• ψητό ≈ psee-TO (very roughly)

χ is a throaty sound with no exact English equivalent. Before front vowels like ι, it is often like the German ch in ich, or a very soft hissy h made further back in the mouth.

So:

• χοιρινό ≈ hee-ri-NO or khee-ri-NO, very approximately

Also note the stress:

• ψητό
• χοιρινό
• αδερφή
• προτιμάει

The accent mark shows which syllable is stressed.